IN THE FIELD By Lori Kuiper
A Modern Approach to Pre-Heating Steel Induction heating for precision welding
Technicians utilize induction heating systems provided by Red-D-Arc, delivering uniform, controlled heat essential for this large-scale steel project.
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recision heat treating is the essential underpinning in everything from steel erection to manufacturing. It’s not just about maintaining material integrity — it’s about ensuring the safety, efficiency and quality of complex projects. Induction heating is a more modern approach to heat treatment. Using electromagnetic fields, a power source sends an alternating current through an induction heating cable and the friction created heats the material without direct contact. This method offers significant advantages over traditional flame heating, enhancing productivity, safety and control. Let’s explore the top five reasons why induction heating can be advantageous for today’s most demanding projects.
1. Material Type Induction heating works particularly well with carbon steel, which is most common in manufacturing and infrastructure projects. Preheating steel, especially for structural welding, is critical to reduce the risk of cracking and to ensure weld integrity. Induction heating ensures precise, even heating, protecting the material from damage and reducing inconsistencies during welding.
2. Desired Heat Range Precise temperature control is vital for preheat and post-weld treatments. Induction heating allows for highly controlled, consistent temperatures, which is especially important in steel erection, where consistent preheat temperatures help
Lori Kuiper is a welding engineer with more than 20 years of experience, including welding equipment manufacture, welding consumables sales, and field weld engineering. She has served on or chaired several technical committees of the American Welding Society and has a deep understanding of heating processes, as well as how to use them in the field. Currently, Lori is the Director of Specialty Products for Red-D-Arc, an Airgas company.
24 | THE STEEL ERECTORS ASSOCIATION OF AMERICA
reduce thermal stress and the potential for weld defects. Unlike flame heating, which is often inconsistent with fluctuating temperatures due to a lack of operator education, induction heating provides uniform distribution, making it ideal for high-stakes projects like bridge building, skyscraper construction, or tunnel work, where precision is critical. Induction heating is also excellent in cold weather applications. In fact, both the American Welding Society (AWS) D1.1 Structural Welding Code and American Association of State Highway and Transportation Officials (AASHTO)/AWS D1.5 Bridge Welding Code have requirements for preheating when welding in cold weather. Using induction heating helps to keep the base materials at the desired level rather than flame heating, which causes the heat to drop off as soon as the flame is removed.